There are a few methods known in the art for preparation of higher molecular weight diamines and triamines. Typical methods for preparing these compounds incorporate the use of polyether polyols.
One method involves the addition of acrylonitrile to polyols followed by hydrogenation. This can be represented as follows: ##STR1## where R" represents H, CH.sub.3 or C.sub.2 H.sub.5.
A second method involves the reductive amination of polyols to amines which can be represented by the following equation: ##STR2## where R" is H, CH.sub.3 OR C.sub.2 H.sub.5.
Polyetherpolyamines prepared by the methods described above can be used in many chemical reactions and applications. For example, they can be used in preparing other functional amine derivatives.
In U.S. Pat. No. 4,362,856 there is disclosed a method of preparing poly-(2-aminoalkyl)polyamine compounds by means of a two-step process wherein a nitroparaffin, an aldehyde and a suitable polyamine are condensed. Subsequently the poly-(2-aminoalkyl)polyamine is used to cure epoxy resins and provide products having good heat flexibility, high heat distortion temperatures and excellent solvent resistance.
U.S. Pat. No. 4,705,814 discloses the reaction product of a polyoxyalkylene polyamine and an aliphatic isocyanate which may be made rapidly without the use of heat or a catalyst.
From a survey of the related art it does not appear that it has been previously known to react nitroalcohols with isocyanate prepolymers or isocyanates to prepare di- and trinitro compounds which are reduced to polyamino compounds. The polyamino compounds are useful for the preparation of polyurea coatings and polyurea RIM products.